This invention relates to a cable suitable for use in connecting integrated circuit elements (LSIs) to each other and a method of producing the same.
In recent years, in electronic apparatuses such as a large scale computer, high-density mounting of circuit components is progressing following the increase in density of integrated circuits. In the electronic apparatuses of the type, integrated circuit elements are connected by a cable to each other.
Referring to FIG. 1, description will be made about a structure of connecting two integrated circuit elements to each other by the use of a conventional cable. The cable depicted by 91 comprises a cable body 92 and a connector arrangement 93 and is interposed between two circuit boards 94 and 95. The cable body 92 comprises a belt-like flexible substrate. The connector arrangement 93 comprises two connectors 93a and 93b attached to longitudinal opposite ends of the cable body 92, respectively.
The connectors 93a and 93b are releasably attached to connectors 94a and 95a mounted on the circuit boards 94 and 95, respectively. The connectors 94a and 95a are connected to integrated circuit elements 94b and 95b mounted on the circuit boards 94 and 95, respectively. In order to connect the integrated circuit elements 94b and 95b to each other, the connectors 94a and 95a mounted on the circuit boards 94 and 95 are fitted to the connectors 93a and 93b of the cable 91, respectively. As a result, the integrated circuit elements 94b and 95b are connected to each other through the cable 91, the connectors 94a and 95a and the circuit boards 94 and 95.
However, the cable 91 connects the two integrated circuit elements 94b and 95b not directly but through the circuit boards 94 and 95 and the connectors 94a and 95b. Thus, an increased number of parts are required for connection of the integrated circuit elements 94 and 95. In addition, a wide space is required for connection of the integrated circuit elements 94 and 95. This results in a problem that the conventional cable can not cope with the high-density mounting of the electronic apparatuses in recent years.
Japanese Unexamined Patent Publication (JP-A) No. S62-291876 discloses another conventional cable. However, an increased number of parts are also required for connection of a well-known pin grid array package. Therefore, the above-mentioned problem is not solved.
It is therefore an object of the present invention to provide a cable and a cable assembly for connecting integrated circuit elements to each other, which is capable of reducing a space required for connection of the integrated circuit elements so as to cope with the recent development of high-density mounting in electronic apparatuses.
It is another object of the present invention to provide a method of producing the above-mentioned cable for connecting integrated circuit elements to each other.
Other objects of the present invention will become clear as the description proceeds.
According to an aspect of the present invention, there is provided a cable for use in connection between integrated circuit elements each having terminals. The cable comprises a cable body comprising an insulator and a plurality of conductors buried in the insulator to have a matrix pattern in section. The cable body has longitudinal end faces as mounting surfaces which are for mounting the integrated circuit elements, respectively. The cable further comprises a plurality of conductor pads formed on each of the mounting surfaces and connected to the conductors for being connected to the terminals of each of the integrated circuit elements, respectively.
According to another aspect of the present invention, there is provided a cable assembly which comprises a plurality of cables as mentioned above and a mounting part for mounting one of the integrated circuit elements. The mounting part is placed between the cables and connected to the conductor pads.
According to still another aspect of the present invention, there is provided a method of producing a cable for use in connection between integrated circuit elements each having terminals. The method comprises the steps of preparing a base member and forming a layered body on the base member. The layered body includes an insulator and a plurality of conductors buried in the insulator to have a matrix pattern in section. The method further comprises the steps of removing the base member from the layered body to form a cable blank, cutting longitudinal opposite end portions of the cable blank to form a cable body having longitudinal end faces as mounting surfaces, and forming a plurality of conductor pads on each of the mounting surfaces to be connected to the conductors.